This invention relates to a substrate conveying system for conveying a substrate such as a semiconductor wafer or a reticle, for example.
A lithographic process in semiconductor manufacture uses an exposure apparatus for printing, by projection exposure, a circuit original formed on a reticle onto a photoresist applied to a wafer. When a reticle is to be supplied into or collected out of such an exposure apparatus, a reticle while being accommodated in a container such as shown in FIG. 11 is introduced into the exposure apparatus. Alternatively, a container is loaded on a load port, provided on the exposure apparatus, and only a reticle inside the container is introduced into the exposure apparatus.
The structure of the container (FIG. 11) will now be described. FIG. 11 is a perspective view of a substrate (reticle) accommodating container in a separated state. The container comprises a supporting member 2a for supporting a reticle 1 having a pellicle 1a attached to the bottom face thereof, a lower tray 2 having a positioning member 2b, for roughly positioning the reticle 1 within a horizontal plane, an upper lid 3 for covering the reticle 1, and engaging means pivotably mounted on the upper lid 3 and engageable with the lower tray 2 to bring the lower tray 2 and the upper lid 3 into an integral structure. Inside the upper lid 3, there is a reticle pressing member 3a for preventing floating of the reticle 1 away from the reticle supporting member 2a on the lower tray 2, as the lower tray 2 and the upper lid 3 are brought into engagement with each other by the engaging means 4.
Between the reticle supporting member 2a and the reticle positioning member 2b of the lower tray 2, there is a space maintained to accept insertion of a fork-like hand for holding the reticle 1 by attraction. The substrate conveying system operates to relatively move this fork-like hand forwardly/backwardly and upwardly/downwardly to transfer and convey a substrate such as a reticle.
Usually, the components of such a substrate (reticle) accommodating container are made by integral molding of a resin material, because of the cost. Additionally, since it is disposed between the fork-like hand and the pellicle frame, the thickness is small. Therefore, after it is used for a long term, deformation or breakage may occur due to an internal strain produced at the time of the molding or to the handling thereof, and the space for insertion of the fork-like hand may not be assured. On that occasion, if the fork-like hand is inserted into the container, it may interfere with supporting components or positioning components, to cause breakage of the reticle or the hand itself. This requires expensive repairs or it causes increased down-time of the machine.
It is an object of the present invention to provide a substrate conveying system by which unwanted interference is prevented with a substrate accommodating container or a reticle where the reticle is to be inserted into or taken out of the container, and which is inexpensive and small in the throughput decrease.
In accordance with an aspect of the present invention, there is provided a substrate conveying system for conveying a substrate to and from an accommodating container having a supporting member for supporting one or more substrates, by use of a hand arranged to hold the substrate by attraction, characterized by an obstacle detector for detecting the presence/absence of an obstacle in a region through which said hand is inserted into said container.
In one preferred form of this aspect of the present invention, the container has a positioning member for positioning the substrate.
The positioning member may function to position the substrate in a horizontal plane.
The presence/absence of an obstacle may be detected at the time of transfer of the substrate.
The conveying system may further comprise a transmission type sensor having an optical axis approximately parallel to the movement direction of said hand and extending between a region in which the supporting member should be placed and a region into which the hand should be inserted, wherein said sensor is relatively moved upwardly or downwardly relative to said supporting member, whereby an obstacle can be detected.
The container may comprise a lower tray unit including a lower tray having said supporting member and said positioning member, an upper lid unit including an upper lid for covering the substrate, and an engaging member pivotably supported by said upper lid and for disengageably engaging said lower tray and said upper lid with each other, wherein said substrate conveying system includes a lower-tray supporting table for supporting and positioning said lower tray of said container, upper-lid holding means for holding said upper lid of said container, and container opening and closing means for releasing said engaging member and for relatively moving said lower-tray supporting table and said upper-lid holding means upwardly or downwardly, and wherein said transmission type sensor is fixedly mounted on said upper-lid holding means.
The obstacle detector may be operable to detect deformation or breakage of said container.
The detection of an obstacle may be performed simultaneously with mapping of the substrate.
The mapping of the substrate may be performed by using the whole of or one of an output of said obstacle detector.
The conveying system may further comprise memory means for storing an output of said obstacle detector, together with the amount of upward or downward motion of said upper-lid holding means.
In accordance with another aspect of the present invention, there is provided an exposure apparatus including a substrate conveying system as recited above.
In accordance with a further aspect of the present invention, there is provided a group of production machines, for performing various processes.
The method may further comprise (i) connecting the production machines of the group with each other through a local area network, and (ii) executing data-communication concerning information related to at least one production machine of the production machine group, between the local area network and an external network outside the semiconductor manufacturing factory.
A database provided by a vendor or a user of the exposure apparatus may be accessed through the external network so that maintenance information related to the production machine can be obtained through the data communication, and wherein production control can be performed on the basis of data communication made through the external network and between the semiconductor factory and a separate semiconductor factory.
In accordance with yet a further aspect of the present invention, there is provided a semiconductor manufacturing factory, comprising: a group of production machines, for performing various processes, including an exposure apparatus as recited above; a local area network for connecting the production machines of the production machine group with each other; and a gateway for enabling an access from the local area network to an external network outside the factory, wherein information related to at least one production machine in the group can be data communicated by use of the local area network and the gateway.
In accordance with a still further aspect of the present invention, there is provided a method of executing maintenance of an exposure apparatus, as recited above and being provided in a semiconductor manufacturing factory, said method comprising the steps of: preparing, by a vendor or a user of the exposure apparatus, a maintenance database connected to an external network outside the semiconductor manufacturing factory; admitting an access from the semiconductor manufacturing factory to the maintenance database through the external network; and transmitting maintenance information stored in the maintenance database to the semiconductor manufacturing factory through the external network.
The exposure apparatus as described above may comprise a display, a network interface and a computer for executing network software, wherein maintenance information related to said exposure apparatus is data communicated through the computer network.
In the exposure apparatus, the network software may provide on the display a user interface for accessing a maintenance database prepared by a vendor or a user of said exposure apparatus and connected to an external network outside a factory where said exposure apparatus is placed, thereby to enable obtaining information from the database through the external network.
The substrate conveying system as described above may further be characterized by a transmission type sensor having an optical axis approximately parallel to the movement direction of said hand and extending between a region in which the positioning member should be placed and a region into which the hand should be inserted, wherein said sensor is relatively moved upwardly or downwardly relative to said positioning member, whereby an obstacle can be detected.
In the structure described above, there is an obstacle detector for detecting the presence/absence of an obstacle in a region into which a hand is to be inserted. If any obstacle is detected, the insertion of the hand is discontinued, such that interference of the hand with the substrate accommodating container can be avoided beforehand.
A transmission type sensor has an optical axis and extends approximately parallel to the movement direction of the hand and extends between a region through which the hand should be inserted into the container and a region in which the substrate supporting member or substrate positioning member of the container should be inherently placed. This sensor may be mounted on an upper-lid holding means to detect an obstacle during the opening/closing motion of the upper lid. Therefore, a decrease of the throughput can be suppressed sufficiently.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.